International Normalised Ratio
Clinical Background:
This is the accepted method for controlling Vitamin K antagonist anticoagulant therapy (primarliy Warfarin). The patients Prothrombin Time (PT) is divided by the laboratory Mean Normal Prothrombin ...
This is the accepted method for controlling Vitamin K antagonist anticoagulant therapy (primarliy Warfarin). The patients Prothrombin Time (PT) is divided by the laboratory Mean Normal Prothrombin Time (MNPT) and the resulting ratio is then raised to the power of the ISI, to convert results to a common WHO standard.
Test Details
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Discipline:
Haemostasis
Haemostasis
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Specimen Container Adult:
Light blue - sodium citrate
Light blue - sodium citrate
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Specimen Container Paediatric:
Light blue - sodium citrate
Light blue - sodium citrate
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Minimum Volume Adult:
2.7mL
2.7mL
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Minimum Volume Paediatric:
1.3mL
1.3mL
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Special Requirement:
Tube must be correctly filled to line, to ensure correct ratio of blood to anticoagulant, ensure adequate mixing.
Tube must be correctly filled to line, to ensure correct ratio of blood to anticoagulant, ensure adequate mixing.
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Sample Stability:
24 hrs
24 hrs
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Transport Requirements:
Samples should be transported to lab without delay
Samples should be transported to lab without delay
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Freq Analysis:
Continuous
Continuous
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Add On Test:
tnu-tr.bloodsciencesadditions@nhs.net (external)
tnu-tr.bloodsciencesadditions@nhs.net (external)
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Quality Assurance:
UK NEQAS Blood Coagulation
UK NEQAS Blood Coagulation
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Reference Ranges:
1.5 - 4.0
Dependent upon specific target value for patient.
1.5 - 4.0
Dependent upon specific target value for patient.
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Other Info:
To monitor warfarin like anticoagulants.
To monitor warfarin like anticoagulants.
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Routine Contact Name:
RVI or Freeman Section Leaders
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Routine Telephone:
RVI: 0191 2820332, Freeman: 0191 2231195
RVI: 0191 2820332, Freeman: 0191 2231195
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Specialist Test:
No
No
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Specialist Contact Name:
Haematology and Haemostasis Healthcare Scientist
Haematology and Haemostasis Healthcare Scientist
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Specialist Telephone:
0191 2139758
0191 2139758
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Specialist Email:
alison.brown93@nhs.net
alison.brown93@nhs.net